1. Field of the Invention
This invention relates to a constriction apparatus and, more particularly, to a constriction apparatus and method particularly adapted to an artifical sphincter wherein the apparatus includes a pair of spaced, parallel, coaxial rings, at least one ring being rotatable, the rings having a plurality of tie members arrayed annularly between the rings so that relative rotation between the rings causes the tie members to move inwardly in a constricting movement toward the axis of the constriction apparatus.
2. The Prior Art In the field of medicine and also medical research, it is frequently necessary to clamp a vessel or otherwise stop the flow of fluid such as blood flow through a vessel. Vascular clamps are well known and generally involve two jaw members which transversely clamp the vessel to shut off the flow of blood. However, it is also well known that vessels such as blood vessels, and the like, have irregular wall thicknesses with corresponding irregularities in the inner wall surface so that a clamp having jaws which move in a parallel clamping action must clamp the vessel tight enough to seal the thinnest portion of the irregular wall surface. Otherwise, there will be leakage past the clamp. Accordingly, the conventional vascular clamp, if used for a significant period of time, results in pressure necrosis of the underlying vascular tissue. While many procedures have been adapted to alleviate this particular problem, it is believed that it would be a significant advancement in the art to provide a novel constriction apparatus and method for gently constricting flow of fluid through a vessel with minimal damage to the vessel through pressure necrosis. Numerous other applications require a constricting-type movement such as encountered in a sphincter-type muscle arrangement wherein the muscular movement contracts towards the axis of the muscular structure. Various other flow control devices could also benefit from an axially oriented constricting movement.
A constriction or crimping apparatus is disclosed by Falconer (U.S. Pat. No. 2,569,850) and includes a plurality of rods mounted circumferentially around an axial opening. A tubing is inserted in the opening and is crimped by twisting the rods about the axis. The basic principle shown by the patent is analogous to the mechanism of the aritifical sphincter apparatus and method of the present invention.
Other constricting devices are shown in the patents of Colley (U.S. Pat. No. 2,434,835); Carlson, Jr. (U.S. Pat. No. 4,092,010); and Kingsford (U.S. Pat. No. 4,194,848). However, these devices use entirely different operative mechanisms from that of the present invention.
It would, therefore, be an advancement in the art to provide a novel constriction apparatus which would provide the basic principle for a sphincter-type orifice muscle for various applications. Such a novel apparatus and method is disclosed and claimed herein.